Concrete retaining wall blocks are used to build any number of landscape structures, such as, for example, raised planting beds and soil retention walls. These structures are generally formed by stacking the retaining wall blocks on top of one another in successive courses. Typically, retaining wall blocks include some type of set-back flange extending from a lower face of the block that is designed abut against a rear face of a block in a course below the block so as to provide a pre-determined set-back distance from the course below and to provide course-to-course shear strength.
FIG. 20A is a perspective view illustrating generally one embodiment of a conventional retaining wall block 870. Retaining wall block 870 includes a front face 872 having a three-dimensional texture, a rear face 874, an upper face 876, a lower face 878, opposing side faces 880 and 882, and a set-back flange 884 extending from lower face 878 along an edge shared with rear face 874. Opposing side faces 880 and 882 are angled inwardly at an angle (θ) 886 from front face 872 such that front face 872 has a width (Wf) 888 greater than a width (Wr) 890 of rear face 14. FIG. 20B is a side view of block 870 and illustrates set-back flange 884 having a set-back depth (Df) 892.
When stacked in courses to form a wall or other structure, each successive course of blocks is set-back from the previous course by an amount substantially equal to a depth of the set-back flange. When the set-back flange is the same on each block, each successive course is set-back from the previous course by the same amount, giving the wall a uniform and geometric appearance. FIG. 20C illustrates an example retaining wall structure 894 formed using retaining wall blocks 870 of FIG. 20A and shows a uniform set-back distance between successive courses of blocks which is substantially equal to the set-back depth (Df) 892 of flanges 884. Such a uniform set-back can be undesirable, particularly when trying to create a landscape structure having a natural appearance, such as that of natural rock or stone.